Chimney caps are designed to be placed on top of and enclose the upper end of a chimney flue. The chimney cap prevents rain, hail, leaves, small animals and other possible obstructions from entering the chimney flue. Chimney caps also prevent birds and squirrels from nesting in an infrequently used chimney. Conventional chimney caps can be formed from a pliable metal material such as steel. The four sides of the cap are conventionally created by bending a single sheet of metal into the four sides in succession. The hood (or roof) of the cap is typically welded onto the side pieces to form a single finished unit. In some chimney caps, flanges are welded to the bottom of each side to form a shelf which is placed on top of the chimney flue and supports the cap. The cap can be further secured by screws on each side of the chimney cap in order to hold the cap in place next to the flue. A chimney cap can also be permanently secured to the chimney by either cementing tabs located on the bottom of the chimney cap to the crown area, applying an adhesive to the chimney cap tabs and the crown area, using masonry screws to bolt the cap directly onto the crown or surrounding area or using any combination of the above or other known techniques.
Multiple flue chimney caps which cover more than one flue are advantageous to use instead of individual chimney caps if two or more flues are located together on the roof of a building. A house may have two or more fireplaces with separate chimney flues and may additionally have a furnace or wood burning stove with a separate flue. Many times in the design of the house, the flues are located next to each other on the roof. Multiflue chimney caps can be used to cover all of the flues with one chimney cap which can save money and improve the overall appearance. Multiflue chimney caps are typically permanently affixed to the flue area and require a removable hood in order to clean one or the more of the covered chimney flues. Permanent chimney caps conventionally attach the hood of the caps with screws, nuts and bolts which must be removed using a tool such as a wrench.
When a chimney flue requires cleaning after normal use, the nonpermanent chimney cap with a welded on hood is normally removed from the chimney by unscrewing the nuts from the bolts on the sides of the cap which hold the cap in place on the chimney flue. This removal operation typically requires a tool such a wrench or pair of plyers to loosen the nuts or screws sufficiently so that the entire cap can be removed. The cap must then be placed safely out of the way on the ground or other area so that the chimney sweep does not injury himself while cleaning the flue. The bolts and nuts must be carefully stored so that they do not fall to the ground or get lost. It would be advantageous to have a removable chimney cap hood which can be removed from the rest of the chimney cap and replaced manually without the need for extra tools and which does not have loose bolts or screws.
A collapsible chimney cap is a cap which can be assembled at the point of installation. A collapsible chimney cap is usually shipped in multiple pieces, typically four individual side pieces, a hood, screws or bolts for holding the cap onto the chimney flue and screws or bolts for attaching the hood to the four side walls. The hood is typically connected to each of the side walls by placing the bolt through the sidewall and the hood. Welding operations are not practical when assembling a chimney cap on the roof. A nut placed on each bolt then holds the hood in the place. While some collapsible chimney cap hoods can be removed since they are not welded, it would normally necessitate using a wrench or plyers to unscrew the nut from the bolt. It is undesirable to perform such a mechanical operation on a roof a house where a chimney sweep or house owner could drop the nuts and bolts or lose his balance and fall from the roof.
It would be advantageous to design a chimney cap with a detachable hood which would allow for easy installation of the hood onto the cap and additionally allow easy removal of the hood when required.